Fatal pulmonary hypertension in identical twins with systemic lupus erythematosus

Identical twins were simultaneously diagnosed with systemic lupus erythematosus (SLE) at the age of 12. Later, both developed pulmonary involvement of SLE including pleural effusions, pleuritis, and recurrent bronchopneumonia. In their last year of life, their pulmonary condition deteriorated and they died of severe pulmonary hypertension at the age of 20. At autopsy, small to large pulmonary arterial walls were markedly thickened. There was no SLE renal involvement. Pulmonary hypertension in SLE without pulmonary parenchyma involvement is extremely rare, with only 18 such cases reported. This is the first report of pulmonary hypertension observed in identical twins with a similar clinical course. This case may suggest the possible genetic fate of pulmonary involvement of SLE.